First Registration

This page covers an SDR cell. For a femtocell, use Femtocell Setup to connect the device, configure its radio, and register a handset.

Checklist

Before starting, confirm:

1xBTS built successfully (Building from Source)
BTS and radio configured (Configuration)
SDR connected and recognized
Docker services running: docker compose up -d
CDMA2000 1x capable handset available

Start the BTS

cargo run --release -p cdma-nib -- \
    --config-dir config \
    --radio-config config/radio_bladerf_micro2.json

On startup the BTS begins transmitting:

Channel	Walsh	What It Does
Pilot	W0	Timing/phase reference — always on
Sync	W32	System time, PN offset
Paging	W1	Overhead messages (SPM, APM, NLM, etc.)

Add the handset in Subscribers with its phone number and IMSI plus ESN or MEID. An IMSI+MEID identity does not require a stored ESN. A handset listed in Mobiles alone does not indicate a subscriber association.

Authentication defaults to monitor mode, which records requested authentication checks without denying service on failure. Provision an A-key before relying on authenticated calls or voice privacy. See Authentication & Voice Privacy for manual and OTASP options.

Registration Flow

When the handset powers on within range:

Step	What Happens
1. Pilot acquisition	Handset searches for and locks onto pilot channel
2. Sync channel	Reads system time, PN offset from sync
3. Paging channel	Receives overhead messages (System Parameters, Access Parameters)
4. Access channel	Handset transmits Registration Message
5. Registration accept	Network resolves the subscriber, discovers MEID if needed, and applies authentication policy before accepting registration. A welcome SMS is sent the first time a new mobile is seen.

Troubleshooting

Symptom	Check
No pilot acquisition	TX frequency, gain, SDR connection
Access probes but no registration	Subscriber in HLR, access parameters
Registration rejected	Subscriber IMSI and hardware identity, A-key state, and authentication results when enforce mode is enabled.
Intermittent access	Power control parameters, RF environment

Next Steps